Small Heat Shock Proteins Protect Electron Transport in Chloroplasts and Mitochondria During Stress

Evidence indicates that small heat-shock proteins (Hsps) areinvolved in stress tolerance, but the specific cell componentsor functions that small Hsps protect or repair are mostly unidentified.We recently showed that the chloroplast small Hsps of higherplants (1) are produced in response to many environmental stresses(e.g., heat, oxidative, and high-light stress); and (2) protect(but do not repair) photosynthetic electron transport in vitroduring stress, specifically by interacting with the oxygen-evolving-complexproteins of Photosystem II (PSII) within the thylakoid lumen.However, in vivo evidence of the importance of these Hsps tophotosynthetic stress tolerance is lacking. Here we report positiverelationships between chloroplast small Hsp production and PSIIthermotolerance in (1) a heattolerant genotype of Agrostis palustris(bentgrass) and a heat sensitive genotype which lacks one ormore chloroplast small Hsps produced by the tolerant genotype;(2) ecotypes of Chenopodium album (lambs quarters) from thenorthern vs. southern U.S. (New York vs. Georgia); and (3) nineLycopersicon (tomato) cultivars/species differing in heat tolerance.These in vivo results are consistent with our previous in vitroobservations and indicate that genetic variation in productionof the chloroplast small Hsp is an important determinant ofphotosynthetic and, thereby, whole-plant thermotolerance. Recently,we showed that the mitochondrial small Hsp of plants protectsrespiratory (specifically Complex I) electron transport in vitroduring heat stress, and here we present evidence for previouslyunidentified small Hsps in mitochondria of mammal (rat) cellswhich also protect Complex I during heat stress. These resultssuggest that the mitochondrial small Hsps, like the small chloroplastHsps, are general stress proteins that contribute significantlyto cell and organismal stress tolerance.     

Predator-induced alterations in Daphnia morphology

The freshwater cladocerans Daphnia pulex and Daphnia schodleriprotect themselves from predation by morphological alterationsinduced in response to water-soluble chemicals released by theirrespective predators. Daphnia pulex is induced by larvae ofthe phantom midge, Chaoborus. Populations of D.pulex which areinduced are those most likely to have intense interaction withthe predator. This is true both on a broad geographic scaleas well as locally Cephalic expansion in D.schodleri is inducedby notonectids, in particular Buenoa sp. This predator preferslarger prey and consequently small instars of D.schodleri showno evidence of induction Both examples of predator-induced alterationssuggest that this type of response is costly to the prey andis manifested only in those individuals and populations mostthreatened     

ROBERTSIELLA SILVICOLA, A NEW SPECIES OF TRICULINE SNAIL (CAENOGASTROPODA: POMATIOPSIDAE) FROM PENINSULAR MALAYSIA, INTERMEDIATE HOST OF SCHISTOSOMA MALAYENSIS (TREMATODA: DIGENEA)

A new species of pomatiopsid gastropod, Robertsiella silvicola,is described from Perak, peninsular Malaysia. The encapsulationof the ducts of the bursa copulatrix complex, short (wide) spermathecalduct and penial stylet indicate that this is a species of Robertsiella.Robertsiella silvicola is distinguished from other Robertsiellaby its small size, the lack of pronounced spiral macrosculptureon the shell, and the nature of the stylet. Robertsiella silvicolais found in water bodies ranging from small, spring-fed, first-orderstreams to tiny trickles of water draining off forested hillsides.This species appears restricted to limestone areas in the foothillsof the mountain chains of Kedah and Perak States, West Malaysia.It appears to be a highly compatible intermediate host for theparasitic blood fluke Schistosoma malayensis Greer, Ow-Yang& Yong, 1980 that infects humans and other mammals in Malaysia. (Received 15 September 2004; accepted 21 March 2005)     

BARNACLE-DWELLING EGOTYPES OF THREE BRITISH LITTORINA SPECIES AND THE STATUS OF LITTORINA NEGLECTA BEAN

On the basis of collections from SW Wales and W Ireland it isshown that small (<5 mm) black and/or white Littorina occurringin the barnacle zone on exposed shores, of the L. neglecta shelltype, comprise three species. From their reproductive anatomythese correspond to L. saxatilis, L. arcana and L. nigrolineata,and are interpreted as analogous barnacle-dwelling ecotypesof these species. This adds to the evidence that L. neglectais not a distinct species, but an ecotype of L. saxatilis. (Received 1 June 1992; accepted 23 June 1992)     

Indirectly fluorescently labelled flagellates (IFLF): a tool to estimate the predation on free-living heterotrophic flagellates

A procedure was developed to estimate the direct grazing impacton free-living heterotrophic nanoflagellates (HNF). Culturedflagellates were labelled by feeding on brightly fluorescingbacteria (FLB) and then offered as indirectly fluorescentlylabelled flagellates (IFLF) to potential predators of HNF. Thenumber of FLB in the predators' food vacuoles could be convertedinto IFLF uptake and consumption of HNF. This new techniquewas used to study the HNF-ciliate relationship in the pelagiczone of Lake Constance. Three groups of ciliates were detectedas HNF grazers: small representatives of the genus Strobilidium.a small Haltena-like ciliate (probably Halteria grandinella)and a Codonella sp. Tintinnidium sp. group The ingestion ofHNF by these groups of ciliates ranged between 3 and 15, 3 and39, and 3 and 7 HNF ciliate^–1 h^–1; respectively.The IFLF method allows the direct determination of ingestedflagellate prey in the food vacuoles of their predators. Becauseindigenous living prey organisms were used, tracer discriminationcan be reduced.     

Phosphate Compounds in Vertebrate Red Blood Cells

This review brings together and discusses the significance ofexisting information about water-soluble (small molecule) organicphosphate constituents of red blood cells in different vertebratespecies, with emphasis on 2,3 diphosphoglycerate (DPG), inositolpentaphosphate (IP₅) ATP and guanosine triphosphate (GTP), compoundswhich may play an important role in respiratory physiology bymodifying the affinity of hemoglobin for oxygen. Results onthe distribution and concentration of these compounds in redcells of vertebrate animals can be summarized as follows 1)DPG High in mammals (except cats and ruminants) Absent in crocodilianssquamata and fishes. High briefly in the bird embryo absentin adult. High briefly in turtle embryo low in juvenile lowto absent in adult 2 IP₅. High in birds. Absent in mammals,crocodilians squamata and fishes (with the exception of Arapaimagigas). Low in turtles 3 ATP Intermediate in mammals. High inbirds and turtles. Very high in squamata Intermediate to veryhigh in fishes. Low in crocodilians 4) GTP Very low in mammalsbirds, reptiles and amphibians (except for small pool in Ranatadpole). Low to very high in fishes.     

Extrafloral Nectaries in Cipadessa (Meliaceae)

This is the first report of an extrafloral nectary (EFN) fromAsian Meliaceae and from subfamily Melioideae. The pinnatelycompound leaf of Cipadessa baccifera has 25–35 small,ellipsoidal EFNs abaxially on the rachis, with occasional EFNson leaflets. EFNs secrete nectar until leaf maturity, then graduallywither. Each convex, ellipsoidal EFN is parenchymatous, withouta palisade epidermis, a delimiting nectary sheath, or any vascularaffiliation. This EFN differs markedly from the typical ‘Flachnektarien’EFN described earlier from neotropical Swietenia species. Cipadessa baccifera (Roth.) Miq., extrafloral nectary, Meliaceae, nectary anatomy     

Omnivory in cyclopoid copepods: comparisons of algae and invertebrates as food for three, differenfly sized species

We examined the importance of algal versus invertebrate preyfor three cyclopoid copepods by comparing reproductive successfor females fed on three diets: exclusively algal food, exclusivelyinvertebrate prey and a combination of algal plus invertebrateprey. The three cyclopoid species represent a distinct gradientin body size: Tropocyclops prasinus mexicanus (small body size),Diacyclops thomasi (medium body size) and Mesocyclops edax (largebody size). Our results provide strong evidence for the potentialimportance of algae in the diet of adult cyclopoid copepods.However, the role of herbivory is dependent on species bodysize. We found that algae are the key dietary factor for reproductivesuccess of the small T.p.mexicanus. In contrast, the availabilityof invertebrate prey had a greater influence on reproductionby the two larger species. Overall, cyclopoid copepods shouldbe generally considered as having the potential to derive theirenergy from either animal or algal sources. This has importantconsequences for interpretations of the forces influencing zooplanktoncommunity diversity as well as for general food web theory.     

THE ROLE OF LYMNAEA AURICULARIA (LINNAEUS) AND LYMNAEA PEREGRA (MULLER) (GASTROPODA: PULMONATA) IN THE TRANSMISSION OF LARVAL DIGENEANS IN THE LOWER THAMES VALLEY

Eleven species of larval digeneans are reported for the firsttime in the UK from the freshwater snail Lymnaea (Radix) auricularia.The latter replaced its congener L. peregra in a gravel pitnear Wraysbury, Berkshire in the Lower Thames Valley and hostedan assemblage of larval digeneans similar to that previouslytransmitted by L peregra. The larval digeneans of L. peregrain small bodies of water in the area were also similar to thosefound in L. auriculania in the gravel pit. This replacementin the role of the host is explained on the basis of morphological,physiological and ecological similarities of the two lymnaeidspecies. (Received 19 February 1992; accepted 27 April 1992)     

A NEW SPECIES OF GRANELEDONE (CEPHALOPODA: OCTOPODIDAE) FROM THE SOUTHWEST ATLANTIC OCEAN

A new species of eledonid octopus is described from the southwesternAtlantic Ocean from depths between 90 and 1000 m off the coastsof southern Brazil, Uruguay, and Argentina. This species, Graneledoneyamana is characterized by having a papillose skin, two welldeveloped 'horns' above the eyes, small gills with 5-7 lamellaeon the outer demibranch, arms with uniserial suckers, 35-80on females and 26-70 on males. The third right arm is hectocotylized,the ligula is small, the calamus is large and well differentiated.Ink sac absent. These characters differ from all other knownGraneledone species from the southern oceans. (Received 22 July 1999; accepted 20 May 2000)     

Nucleotide Sequence of cDNA for Concanavalin A from Canavalia gladiata Seeds

We have determined the nucleotide sequence of Con A cDNA forconcanavalin A (Con A) from Canavalia gladiata using a plasmid(pCONAl) that was isolated previously [Eur. J. Bio-chem. (1988)170: 515-520]. This sequence contains a 870-bp open readingframe, a 63-bp 5'-un-translated region and a 99-bp 3'-untranslatedregion. DNA blot analysis suggested that Con A is encoded bya small gene family. In contrast to the case of canavalin, thenucleotide sequence and the genomic organization of Con A geneare highly conserved between C. gladiata and C. ensifor-mis. (Received August 4, 1988; Accepted November 21, 1988)     

吸虱昆虫群落数量分类及其与小兽宿主的协同进化关系

以云南省16种主要小兽宿主体表吸虱群落为分类单元,以基于共54个群落特征变量的各群落优势虱种的相对优势度D_r、染虱率R_L、虱指数I_L、总染虱率R_LT和总虱指数I_LT及各群落的结构参数（平均丰富度 、平均均匀度 、平均多样性指数 及平均优势度指数 ）来探讨云南省吸虱昆虫与其宿主协同进化的关系。运用SPSS12.0统计软件中的系统聚类分析,对16种主要小兽宿主体表吸虱群落进行数量分析。结果将16种小兽宿主体表吸虱群落分为8个类群。隶属同一个属的小兽,其体表吸虱群落相似程度高,在系统聚类分析中聚为一类; 大多数吸虱群落相似性大小与相应小兽宿主在动物分类上的近缘性高低呈高度一致。结果提示： 吸虱昆虫与其所寄生的小兽宿主存在同步进化的关系,特定的小兽宿主,其体表吸虱群落的构成比较稳定,宿主动物的近缘关系越近,其体表吸虱群落的相似性越高,这是吸虱昆虫与小兽宿主协同进化的一个重要生态学证据。     

Shoot Dry Weight, Chlorophyll and UV-B-absorbing Compounds as Indicators of a Plant's Sensitivity to UV-B Radiation

When studying the effects of ultraviolet-B (UV-B) radiationon plants, a good measure of UV-B sensitivity is a decreasein dry weight, since this reflects the cumulative effect ofmany small disruptions in plant function. Measurements of chlorophyllconcentration and the level of UV-absorbing compounds are alsoused to gauge plant health during and after UV-B exposure. Whena variety of vegetable crop plants were screened for UV-tolerance,it was found that the levels of chlorophyll and UV-absorbingcompounds did not correlate with sensitivity. Biomass accumulationwas, however, correlated with UV-sensitivity; plants that accumulatedmore biomass over a 2-week period were more likely to be UV-Bsensitive. This suggests that a rapid growth rate renders plantsmore sensitive to the injurious effects of UV-B radiation. Copyright2000 Annals of Botany Company UV-B radiation, UV-absorbing compounds, chlorophyll, biomass production, UV-B sensitivity, Capsicum frutescens,Cucurbita pepo , Chicorium endivia, Lactuca sativa, Phaseolus vulgaris, Solanum melongena, Spinacia oleracea, Sinapis alba     

Size-dependent trait-mediated indirect interactions among sea urchin herbivores

Despite their importance in community interactions, nonlethalindirect effects of predators are not well understood in manymarine food webs. In this study, I found that within a guildof herbivorous sea urchins, small urchins (Strongylocentrotusdroebachiensis and small Strongylocentrotus franciscanus) alteredgrazing rates in the presence of the predatory sea star (Pycnopodiahelianthoides) and were highly preferred by the predator. Incontrast, large urchins (adult S. franciscanus) did not significantlyalter grazing in the presence of cues from the sea star and,when immobile, were less frequently attacked by the predator.However, the sea star's preference (active predator choice)was obscured by sea urchin mobility, that is, small S. franciscanuswas only most preferred when unable to escape. These resultssuggest that by identifying the relative threat of predationfacing guild members and the degree to which individuals transmittrait-mediated indirect interactions, these indirect effectsmay be predictably incorporated in community interactions.     

Change in the solubility of crystalline Fraction I proteins correlated with change in the composition of the small subunit

Fraction I protein crystals were obtained by a simple methodfrom four additional species in addition to seven species ofNicotiana previously reported and from Solanum melongena. Crystalswere obtained neither from several other genera of the Solanacealnor from N. debneyi, but ¹⁴C protein from the latter co-crystallizedwith N. tabacum Fraction I protein. Co-crystallization did notoccur with ¹⁴C proteins from species of Tagetes, Allium, Beta,Brassica and Hyocyamus whose Fraction I proteins were evidentlytoo different in their quaternary structures to occupy the samecrystal lattice with N. tabacum protein. Fraction I proteinsfrom N. gossei and N. excelsior differed in solubility as afunction of the NaCl concentration. The two proteins were alikein the isoelectric point of the three primary peptides composingthe large subunit, but differed in the isoelectric point ofone out of four primary peptides of the small subunit; thisdifference was also consistent with a difference in trypticpeptide fingerprints. Proteins from N. tabacum and N. glaucadiffered both in the composition of their large and small subunitsbut did not differ in solubility. However, by changing the compositionof the small subunit without changing the large subunit, thesolubility of each protein was changed. The change in smallsubunit composition could be achieved by isolating proteinsfrom the reciprocal F₁ hybrids of N. tabacum ? N. glauca wherethe maternal inheritance regulates the composition of the largesubunit, whereas both maternal and paternal genes regulate thecomposition of the small subunit. ¹Present address: Department of Physiology, Hyogo College ofMedicine, Nishinomiya, Hyogo, Japan. (Received March 20, 1974; )     

Observations on the vertical distribution of zooplankton, including post-larval teleosts, off Plymouth in the presence of a thermocline and a chlorophyll-dense layer

During 1973 – 1977, when Sagitta elegans was returningto dominance over S. setosa in Plymouth waters, there was often,in summer in stratified conditions, a community characterizedby S. setosa in the warm water above the thermocline, and atypical S. elegans community in the colder layer below the thermocline.This vertical separation persisted at night even though somespecies from the S. elegans community migrated up into the warmlayer. Such vertical migration was not stopped by a temperaturediscontinuity of from 3° to 6°C, but fewer individuals,or a lesser proportion of species, took part at the higher temperaturedifference. Only a small part of the zooplankton, comprisingsmall individuals of Limacina retroversa, the appendicularians,and, possibly, post-larvae of Arnoglossus laterna, showed signsof aggregation at the thermocline or the chlorophyll maximumclose to it.     

Localization and Characterization of a Novel 20 kDa Polypeptide in the Chloroplast of the Green Alga Dunaliella salina

Recent work with the green alga Dunaliella salina showed thepresence of a {small tilde}20 kDa chloroplast protein that wasrecognized by polyclonal antibodies raised against the isolatedLHC-II [Webb M.R. and Melis A. (1995) Plant Physiol. 107: 885].In this report, a characterization of the {small tilde}20 kDapolypeptide is presented. It is shown that it is localized inthe chloroplast envelope membrane of D. salina. The abundanceof this protein is constant on a per cell basis and independentof the light regime during cell growth. The {small tilde}20kDa polypeptide is easily degraded to a {small tilde}19 kDaproduct during sample preparation. A limited amino acid sequenceof 21 residues from the free N-terminus of the {small tilde}19kDa product was obtained. On the basis of this partial sequence,it was concluded that the {small tilde}20 kDa polypeptide isnot a degradation product of a known LHC-II but rather a novelprotein. The {small tilde}20kDa polypeptide did not cross-reactwith antibodies raised against the Cbr (carotene biosynthesis-related)gene product and showed a different electrophoretic mobilityfrom the latter. Light-shift experiments suggest that the {smalltilde}20 kDa polypeptide is not an ELIP (early light-inducibleprotein). Possible functions of the {small tilde}20 kDa proteinare discussed. ¹Permanent address: Department of Biochemistry, University oflund, PO Box 124, S-221 00 Lund, Sweden     

Bicapitate Nitzschia species: abundant nanoplankton in aggregates during November-December (l992) in the equatorial Pacific

From 12°S to 9°N-140°W on the benthic cruise ofthe US Joint Global Ocean Flux Studies (JGOFS), horizontal near-surfacenet tows (n = 18) and vertical net hauls (n = 15, 200-0 m) yieldedhigh relative abundances of small, bicapitate, intact Nitzschiavalves (average 59.0 and 56.0% of total diatoms, respectively),although >90% of them were too small to have been caughteffectively with the net used. This complex was much less common(average 3.2% of diatoms) in the surface sediment samples (n= 7, 12°S-9°N, below water depths of 4269-4991 m). Examinationunder the light microscope showed concentrations of cells associatedwith organic detritus, planar and cylindrical membranous structures,fecal pellets, and occasionally on other diatoms (e.g. Asterolampra),i.e. on or within particles large enough to be collected inthe net. Although Nitzschio bicapitato Cleve has been consideredto have a characteristic range of shapes, and has often beencited from open-ocean habitats in nano- and microplanktonicstudies, a scanning electron microscopic study revealed severalspecies in our material. Examples of larger and smaller speciesare given, and Nitzschia ikeanae G.Fryx. & H.Lee, sp. nov.,is described here. Ecologically, these observations indicatethat although some are grazed and have been seen aggregatedin fecal pellets, these small pennate diatoms can affix to andgrow on substrates, termed ‘pseudo-benthic habitats’in the open ocean, resulting in unexpected concentrations thathave implications for their life histories and sexual cycles,selection or avoidance by grazers, sinking on substrates, androles in the recycling of nutrients in near-surface waters.     

厚壳贻贝养殖群体与野生群体线粒体DNA的遗传分析(英文）

采用线粒体DNA COI基因序列对厚壳贻贝2个养殖群体与2个野生群体的遗传多样性进行了研究。4个群体共获得30个单倍型。结果显示：在养殖群体中单倍型的数量和遗传多样性要比野生群体的低,可能是由于只有少量的有效父母本对养殖群体的遗传变异有贡献所致。养殖群体与当地野生群体之间也未发生显著的遗传分化,可能是因为它们之间存在基因流。在今后厚壳贻贝养殖过程中,本研究可以用在对养殖群体进行遗传监测,从而保证养殖群体的遗传多样性水平。     

TWO NEW SPECIES OF THE GENUS ISLAMIA RADOMAN, 1973 FROM ITALIAN ISLANDS (PROSOBRANCHIA, HYDROBIIDAE)

Two new Italian species of the genus Islamia (Prosobranchia:Hydrobiidae), one living in eastern Sicily (I. cianensis), andone on Elba Island (Tuscan Archipelago, Italy) (I. gaiteri)are described. The two species are distinguished on the basisof shell and anatomical characters, mainly those of the malegenitalia. I. cianesis n. sp. is characterized by a valvatoidshell and a penial lobe with internal band of glandular tissuenot distinct in its lower portion from the penis body but bulgingapically as a small knob. I. gaiteri n. sp. is characterizedby a planispiral shell and a small lateral penial lobe withoutinternal glandular tissue. (Received 20 December 1993; accepted 27 June 1994)